To put this in perspective, see Charles Tart bio on Wikipedia: <a href="https://en.wikipedia.org/wiki/Charles_Tart" rel="nofollow">https://en.wikipedia.org/wiki/Charles_Tart</a> - his book "Altered States" was quite famous at the time, and inspired the book "Altered states" by Paddy Chayfesky, that in turn became an iconic movie by Ken Russell in 1980.